A very substantial proportion of all ice cream consumed reaches the consumer in the form of a small ice cream bar having a thin exterior coating of chocolate covering its surface. These bars are prepared by dipping the solid ice cream in a sweet chocolate liquid and then withdrawing it. The chocolate liquid solidifies at ice cream teperature forming a thin chocolate coating that covers the exterior of the ice cream bar.
In the usual commercial practice, the ice cream manufacturer prepares the ice cream bars and chocolate processors prepare chocolate liquids in finished form ready for immediate use in coating the ice cream bars. These liquids are shippd to the ice cream manufacturers in steel drums or in tank-trucks, or tank cars.
Representative chocolate liquids suitable for coating ice cream bars are commonly prepared by stirring together cocoa powder, sugar, salt, vegetable oil, milk powder and lecithin with a vigor and for a time to produce a moderately stable dispersion of the solids in the vegetable oil. Chocolate liquids of this kind are manufactured and sold in very large volumes. While these liquids have been extensively used over a long period of time and yield an acceptable product, their use requires constant and expensive attention to cope with certain problems which arise out of inherent properties of the liquids. When these liquids stand in storage, they tend to solidify at ambient temperature. If they are stored in drums, it is necessary to store the drums in a heated storage space in oder to maintain the liquid in a sufficiently fluid form to permit it to be poured from the drums into the dipping vessel. If they are stored in large storage tanks, it is necessary to jacket the tanks and supply sufficient steam or hot water to the jacket to keep the liquids in fluid form. During storage over the periods commonly experienced in commercial use of these materials, the solid components settle out of the vegetable oil forming heavy mud-like deposits in the bottoms of the containers. Where the container is a drum, it is necessary to subject the contents of the drum to agitation for considerable periods in order to put the solids back into reasonably uniform dispersion in the oil. Where the liquids are stored in larger tanks, it is necessary to supply continuous agitation to these tanks in order to maintain the solid components in suspension and so permit withdrawal of a reasonably uniform dispersion of solids in oil from the bottoms of storage tanks. These problems can be coped with an are coped with, but coping with them is a continuous expensive nuisance.